Furnaces foe smelting lead oees



DAVID r. WEBSTER, 'OE' NEW YORK, N. Y.

Letters PatentNo. 76,364, dated April 7, 1868.

IMPROVEMENT IN-FURNAGES FOR SMELTING LEAD GRES.

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TO WI-IOM IT MAY UONGERN:

Be it known that I, DAVID P. WEBSTER, ofV New York, in the county and State of New York, have invented certain new and useful Improvements in Furnaces for Smelting Lead Orcs; and I hereby declare the following to be a full, clear, and exact description of the same, reference being had to'the accompanying drawings, in which- Figure 1 is a side view of my improved furnace.

Figure 2 is an end view of the same.

Figure 3 is a longitudinal vertical section of the furnace.

Figure 4 is a section on the line arg/,iig 3.

Furnaces of ordinary construction for smelting lead ores are liable to the great objection that the bed is vapt to crack and permit the leakage or escape of the melted lead, which, accumulating underneath the bed,

causes it to become displaced or thrown out of proper position. During the smeltingof from twenty (20) to thirty (30) tons of ore, this often occurs to such an extent as to render it necessary to rebuild the furnace, which gives rise not only to great expense, but delays considerably the operation of the works. As, moreover, the

leakage occurs irregularly, dependence cannot be placed upon the apparent yield of the ore asthe true quantity produced, the whole value not being realized before taking down the furnace. The smelting 'of lead ores with iron also acts quite rapidly on the fire-brick, wearing away the"slopes" of the furnace toisuch an extent that the lead ceases to flow to the tap-hole.

My improvements remedy the above defects, as will now be explained by reference to the accompanying drawings.

In order to build my furnace, I construct a wrought-iron pan or jacket, A, of boiler-plate iron' riveted together. This jacket or pan is supported on brick piers B, asA shown in g. 3. A wall, C, of one brick in width, is next built within the pan on each Aside to about the height at rst of two feet. The pan is thenplled with a mixture of wet silica and fire-clay, in about the proportionsof one-third of the latter whenthe furnace is designed for reducing sulphides o r phosphides of lead by iron.: This mixture a is firmly-packed to the height required for the bottom or bed, the required slopes being formed, as shown in iigs. 3 and 4, towards the tap-hole. The outer wall'is then carried upwards a foot or more, and also another wall ofthe same thickness, of common brick, is built within this wall, leaving a space of eighteen inches` between them,` the inner wall resting on the packed bed described. The space between these-two walls is then firmly packed with the same mixture employed in forming bed. The elevation of the walls and packing is continued until the required height for supporting the arch is atta-ined. A centre of common brick is then formed, and over this centre the mixture of silica and clayis packed to a depth of from Vnine to twelve (12) inches. The iire-boxiDiis thenbuilt in the ordinary manner, the flue E leading from the reverberatory tothe smoke-stack being completed by building wallsh` on the arch, as shown in fig. 4, and covering the line, thus formed, with tiles G of fireclay. The whole top surface i of the arch is then covered to a. depth of a few inches with dry sand. A gentle're is then built in the {ire-box,`

and is maintained for about four days, after which the heat should be augmented until the walls become red hot, and this degree of heat is maintained fortwo (2) days longer. Theinncr walls and'centre of common brick are then removed by long rods, tongs, and hoes, leaving the'whole interior of the furnace formed of the packed and concrete mass of silica and clay. When the common bricks of the centre and walls have been removed, the interior of the furnace is heated to a white heat, and if` there be any cracks, they shouid be filled with the drysilica alone.

In a furnace ofthis construction I am able to smelt, with very little repairing,-ve hundred (500) tous of" ore on an average before the furnace requires to be rebuilt. The economy of the`furnace'will at once be manifest by refer-ence to/what has above' been stated concerning furnaces constructed the ordinary manner.

The slight repairs occasionally needed are elected Aby the use of the same mixture of which the bed is formed. The repairing is'accomplished while the furnace is heated, and with little-delayor interruption of the operation of smelting.

'Ihe silica employed is conveniently obtained asthe white sand used in glass-works to make Hint-glass. The clay may be any good quality of fire-clay used for making fire-brick of the best quality.

Having now described my invention, -what I claim as new, and desire to secure by Letters Potent,l is- 1. The method herein-deseribed of formingv the interior or lining' of furnaces, that is to say, by building the bed, walls, and arch of the plastic material herein described, or the substantiel equivalent thereof, in the manner shown and specified, and subjecting the same, when formed into shape, to heat, as herein set forth.

2. The use and employment of the ingredients herein described, for repairing cracks or other injuries, or parts worn by the action of iiuxes, substantially as herein set forth.

3. The combination, with the' furnace, of an iron casing-or pen under the arrangement herein shown and described, so as to support the plastic structure of the furnace, and also allow. free passage of air under and around the same, as and furthe purposes set forth.

I In testimony wheeol have'signed my name to this specification before two subscribing witnesses.

D. P. WEBSTER.

vWitnesses:

M. BAILEY, A.` PoLLoK. 

